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Gamma Filter
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<p>The Gamma filter allows for adjustment of the gamma of the luminance.  Gamma is 
normally defined as a power function and defines the amount of output generated by a 
given input signal.</p>
<p>The gamma filter operates in one of two modes
<ol>
<li>Simple Gamma mode.  In this mode "Use stored Gamma table" is off and the single 
"Gamma" setting is used to adjust the input luminance. Higher gamma values (more thna 1000) can be used 
to increase black detail and lift mid tones at the expense of white detail.  Lower gamma values do the reverse.</li>
<li>Use Stored Table. In this mode "Use stored Gamma table" is on and the filter uses a lookup table to convert input luminace values to the output.</li>
</ol>
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<th>Setting</th>
<th>Default</th>
<th>Description</th>
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<td>Black Level</td>
<td>0</td>
<td>This is the input luminace level that is defined to be black.  This setting 
can be used to adjust for situations where there is a high black level on input.</td>
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<td>White level</td>
<td>255</td>
<td>This is the input luminace level that is defined to be white.  This setting 
can be used to adjust for situations where there is a low white level on input.</td>
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<p>To use the stored gamma table feature you must create an Gamma.ini which is 
placed in the DScaler directory.  This file should have the following format:</p>
<pre>
; Input Luma on left
; Output luma on right
[Gamma]
0=255
1=254

; ... other values

127=128
128=127

; ... other values

254=1
255=0
</pre>
<p>This sample would cause the video to invert.</p>
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